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This article provides a detailed description of the tadpole of the Hyloxalus nexipus frog species, focusing on its geographic variation and morphological characteristics. The researchers collected specimens from Ecuador and Peru and examined their coloration and measurements. The document emphasizes the importance of studying tadpoles in understanding anuran species. It also discusses the morphology and characteristics of tadpoles belonging to the Hyloxalus genus of poison dart frogs, noting specific differences in the upper jaw sheath and the position of the upper fin in Hyloxalus nexipus tadpoles. The information is based on detailed observations of single specimens in different developmental stages and references other relevant studies on tadpole morphology and taxonomy. [Extracted from the article]

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Copyright of Salamandra is the property of Deutsche Gesellschaft fuer Herpetologie und Terrarienkunde eV and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Anuran amphibians have intensively been studied to understand Amazonian biodiversity. Improved methods and sampling has revealed that many widespread nominal species in fact are complexes of species with smaller allopatric ranges. Pan-Amazonian anuran species are rather an exception. In a case study using the three-striped poison frog (Anura: Dendrobatidae: Ameerega trivittata), we ask how the pan-Amazonian distribution of this taxon can be explained and hypothesize that dispersal has played a major role. Species delimitation and intraspecific relationships of the study species were examined from novel and existing (GenBank) sequences of the mitochondrial 16S rRNA gene from 108 specimens of 38 localities using maximum likelihood and Bayesian methods. We performed BioGeoBEARS models using a time-calibrated population tree to reconstruct the biogeographic history. Our results support that A. trivittata is a pan-Amazonian species scattered over its geographic range. Being of Late Miocene origin, the species rapidly spread into newly available space and repeatedly dispersed for-and backward, while vicariance played a major role only in the Early Pliocene. We suggest that intrinsic morphological and life history characteristics (adult size, relative reproductive success) make A. trivittata a more successful disperser than other species, so that riverine barriers are more permeable and hamper allopatric speciation. We conclude that there is no universal causality explaining Amazonia biodiversity, because species-specific biological characteristics are key determents of biogeographical histories. Comparatively better dispersal advantages foster larger geographic ranges and can explain pan-Amazonian distributions. [ABSTRACT FROM AUTHOR]

Harlequin toads (Atelopus spp.) constitute one of the most threatened amphibian clades worldwide, yet much of their life history remains poorly understood. These anurans are strongly associated with stream environments, which are used for reproduction and occupied by males throughout the year, while only visited by females during the reproduction season. We studied a population of the Atelopus flavescens complex in French Guiana. We describe male population density, habitat use, site fidelity and movement, as well as home range behaviour – all prior to the arrival of females. We also present further natural history observations such as nocturnal resting sites and anecdotal observations of females. Our findings suggest that in this lowland population of Atelopus, males maintain territories for a relatively long time compared to other species. Within them, they acoustically compete for females, which they attempt to clasp for amplexus when they arrive later in the season on their way to the breeding sites. [ABSTRACT FROM AUTHOR]

The presence of the parasitic amphibian chytrid fungus Batrachochytrium salamandrivorans (Bsal) in the Eifel Mountains, Germany, was confirmed in 2015. Since then, monitoring of selected populations of the European fire salamander (Salamandra salamandra) has been established. This species is highly sensitive to the pathogen and infection is commonly lethal for individuals within several days, which gave rise to the term 'salamander plague'. Because of the low detection probability of the terrestrial phase of the salamanders, we assessed the status of populations by monitoring the abundance of aquatic larvae as a proxy. A standardized removal sampling was conducted between 2015 and 2019 in 40 creeks in the Northern Eifel Mountains (21 sites with consistent 5-year data) and in 21 creeks in the Southern Eifel Mountains (17 sites with consistent 5-year data). While in the northern Eifel the pathogen was detected in 2015 and is known to be present since 2004, in the southern Eifel Bsal-sites has been confirmed since 2017. In both regions, the number of pools was the best fitting explanatory variable for abundances and detection probabilities of larvae. Indications for larval decline were observed in some creeks with Bsal presence while in others capture rates and larval abundances did not significantly change or sometimes even increased when Bsal was present. As a result, our data do not indicate an effect of the salamander plague to consistently and immediately causing declines in larval abundance. However, these findings remain tentative, and final conclusions should not be drawn yet. The applied removal sampling method is suggested to represent a time- and cost-effective as well as feasible means to obtain long-term population information on larval abundance in the European fire salamander. [ABSTRACT FROM AUTHOR]

The salamander plague, caused by the amphibian chytrid fungus Batrachochytrium salamandrivorans (Bsal), is one of the most devastating amphibian diseases, currently threatening the entire Western Palearctic caudate diversity with extinction. Apparently of Asian origin and recently introduced into Europe, Bsal is known from currently ca. 80 sites in the wild in four European countries. Germany is the Bsal 'hotspot', with more than half (N = 50) of all known European records to date. We here present data based on > 8,500 caudate specimens sampled for Bsal mainly via skin swabbing and quantitative real time PCR (> 3,300 since 2019). Within regions of Bsal occurrence ~ 6-7% of the studied caudates were Bsal-positive. The oldest known European record of the pathogen is from this country (2004), but a massive Bsal dispersal has only been recognized within the last five years with 17 new Bsal sites since 2019 alone. Currently, Bsal is spreading within the northern and the southern Eifel and -- since 2017 -- the Ruhr District. Most recently, the pathogen was for the first time detected in southern Germany (Bavaria) and a further range expansion is expected. A new species distribution model (SDM) of Bsal based on > 100 native and invasive records predicts suitable areas in most parts of Germany. Bsal affects all five caudate species known from these regions and has catastrophic effects on the European fire salamander (Salamandra salamandra). All affected populations in Germany (as well as Belgium and The Netherlands) have dramatically declined. While some may have become extinct due to the salamander plague, in most Bsal-positive sites European fire salamanders can still be recorded at low numbers (at least via systematic larval surveys), and at least one population seems to have recovered as currently Bsal detection remains negative. Little is known about the effect of Bsal on newts, and both prevalence and individual infection load can vary greatly over time, even within one population. However, the situation of the northern crested newt (Triturus cristatus) is alarming, as this species also undergoes declines due to Bsal invasions at some sites. Although some anurans are suggested as potential Bsal reservoirs and transmitters, we detected Bsal in only one individual of the common frog (Rana temporaria) out of 365 anurans of various species tested. Co-infection of Bsal with the related chytrid taxon Batrachochytrium dendrobatidis is known from three taxa (S. salamandra, T. cristatus, Ichthyo saura alpestris) and at four sites. The alarming data from Bsal in Germany call for immediate conservation action at all levels, including ex situ conservation. We therefore strongly support the establishment and implementation of a national Bsal Action Plan. [ABSTRACT FROM AUTHOR]

The European fire salamander (Salamandra salamandra) is a widespread species that occurs in a variety of habitats throughout its range. We studied if different environmental parameters influence presence as well as abundance of larvae within different local landscape units across a more than 5,000 km² large Central European study area. This knowledge is crucial to differentiate between habitat specific absence/low abundance and externally triggered extinctions or population declines, e.g. through newly emerging infectious diseases. Within our study area, the salamander plague, caused by the invasive fungus Batrachochytrium salamandrivorans, has recently been invoked as major factor for population declines in S. salamandra. We estimated larval habitat preferences of 135 European fire salamander populations (presence-absence only), and estimated larval abundances in 85 out of them. In the entire study area, regardless of landscape units, presence of European fire salamander larvae was positively affected by low elevation, a high number of pools (preferred larval microhabitats) and a high amount of consumable macrozoobenthos in the reproduction creeks as well as a high proportion of forest cover in the surrounding terrestrial habitats. Apart from some minor differences among landscape units when they were analysed separately, we observed in many cases a positive effect of a high number of pools (11 out of 56 overall models = 20%) and, furthermore, a negative effect of a late mapping date (mainly due to larval drift caused by heavy rainfalls in early summer and metamorphosis) on larval abundances (12 out of 56 overall models = 21%). Consequently, at least in this Central European study area, which includes mountainous regions up to 700 m a.s.l. ('West- and Osteifel', 'Hunsrück'), a mainly agriculturally used lime soil plateau ('Gutland') and a river valley ('Moseltal'), these habitat preferences can be used to differentiate between habitat-caused and disease-caused absence of European fire salamanders and also population declines using the larval population. [ABSTRACT FROM AUTHOR]

Emerging infectious diseases are one of the main suggested reasons for global amphibian decline. Fungal agents play a key role. Since its introduction, the Asian pathogen Batrachochytrium salamandrivorans has driven the European fire salamander, Salamandra salamandra, to the edge of extinction in the Netherlands and caused severe population declines in Belgium and Germany. We screened 1,526 amphibians (1,431 urodelans and 95 anurans) from 50 sites in a 1,500 km² large area in Germany, south of the next known infected populations. Furthermore, we conducted a presence-absence mapping of larval salamanders in 88 randomly selected creeks and creeks where salamanders had been reported in the past using a standardized removal sampling approach. Our results revealed an expanded distribution of the pathogen in Western Germany and we could detect seven infected urodelan populations including the southernmost locality of the fungus in its exotic range. Larval salamanders were found in 54 out of 63 creeks south, but only in seven out of 25 creeks north of a highway that divides the study area. Bsal infection could mainly be detected in newts (Ichthyosaura alpestris and Lissotriton helveticus) because many previously known European fire salamander populations most likely disappeared in the affected forest regions, however, silently and without observed mass mortalities. The only detectable salamander population north of the highway was found to be Bsal-infected at high prevalence in 2019, but not from 2016 to 2018, suggesting a recent infection event. Overall, prevalence at the individual (2.6%) and population level (14%) was very low. Moreover, modelling habitat suitability in seemingly unaffected areas suggests that most reproduction creeks and surrounding land habitats in the seemingly affected area are still suitable for S. salamandra, supporting our suspicion that the absence of the species is disease-related rather than habitat related. [ABSTRACT FROM AUTHOR]

The chytrid fungus Batrachochytrium salamandrivorans (Bsal), recently introduced from Asia to Europe, causes mortality in numerous species of salamanders and newts and has led to catastrophic declines and local extinctions of the European fire salamander (Salamandra salamandra) in the Netherlands, Belgium, and Germany. Due to the continuous spread of the pathogen, Germany can be considered as the current 'hotspot' of Bsal-driven salamander declines. The pathogen was detected in 2015 in the Eifel Mountains where it probably has been present at least since 2004. Moreover, Bsal was found in 2017 in the Ruhr District where it also might occur since 2004. The Ruhr District is a heavily urbanized and industrialized region in western Germany, which offers an unprecedented opportunity to monitor range expansion and infection dynamics of Bsal in an area affected by intense human activities. We here review the current knowledge on Bsal in the Ruhr District where the pathogen by now has been recorded based on qPCR data from 18 sites distributed over eight cities. Transect counts (adult salamanders) and larval removal-sampling at two sites where Bsal was recorded in 2017 and 2018, confirm that fire salamander populations at the affected sites have declined dramatically. However, single negative-tested individuals were still observed and reproduction could be ascertained. Moreover, we successfully detected Bsal by analysing environmental DNA (eDNA) from samples obtained from a standing water body as well as a stream. Detailed monitoring of a site in Essen (Kruppwald) from January to May 2019 provided data on infection and disease dynamics during an acute Bsal-outbreak in a population of European fire salamanders. After initial observation of single dead infected salamanders in January and February 2019, the maximum Bsal loads in the population ranged from 7.90E+03 ITS copies in early March to 2.29E+09 ITS copies at the end of March. Prevalence of infection ranged from 4% to 50% and significantly increased over time; prevalence of externally visible disease symptoms peaked on May 2 and May 8. Single dead salamanders were encountered throughout the monitoring period. Recaptures of two infected salamanders indicated an increase of Bsal load by about one order of magnitude within one week. Infected salamanders showed small-sized regular round ulcerations usually of 0.25-1 mm but sometimes up to 2.5 mm in diameter, which gave the impression of outward growth from the centre of each ulceration. Among salamander individuals monitored in the Kruppwald, such ulcerations were only found in infected salamanders, but we found no significant correlation between the intensity of the ulcerations and Bsal load. Heat treatment proved effective to cure even deep ulcerations when salamanders were kept for 10 days at 25-27°C or 14 days at 25°C, but infection persisted and ulcerations reappeared six weeks after the end of the treatment; only heat treatment at 25°C for 21 days proved effective to reliably clear the infection in three tested salamanders. [ABSTRACT FROM AUTHOR]

We studied the knowledge gap in GenBank with regard to the ca. 600 anuran species from Amazonia. The markers 12S, 16S, COI and cytb were examined, on which information was available for about half of all species. Both the number of sample sites and the number of samples per species varied greatly (best studied each in 16S: 4.85 ± 10.37; 11.19 ± 31.20), and merely one fifth of all species had at least 5 sample sites. This suggests that a considerable portion of species is underrepresented in GenBank. Representativeness is especially difficult to assess in widespread species that at the same time could well represent cryptic allopatric species (i.e., with smaller distributions). This is a well-known phenomenon in Amazonian anurans considering that truly widespread species do exist. Moreover, limited sampling may not necessarily be the result of limited representativeness, as numerous species are known to occupy relatively small localised to regional ranges only. Our study furthermore revealed that in a geographic context, major portions of Amazonia have as yet been undersampled. That is, the total of 453 sample sites (most with more than one species sampled) are spatially clustered, often in areas with increased anthropogenic activity. We conclude that there is a large knowledge gap in terms of spatial sampling, resulting in taxonomic deficiencies. [ABSTRACT FROM AUTHOR]

Neotropical poison frogs (Aromobatidae, Dendrobatidae) are known for their complex behavior including site fidelity and home range maintenance. It has been shown in a few poison frog species that these amphibians are able to return to their home ranges after experimental translocation. In this study we asked if Ameerega trivittata can be allocated to the species performing homing behavior. In this taxon, males and females show home range behavior, while sexes were not distinguished in our study. Fieldwork was carried out in a wild population at Panguana (Peru), using replacement distances of 150 m, 600 m and 900 m. In total, 79 frogs were translocated. Most rapidly returned to their home ranges from all translocation distances, with a decrease of the homing success with longer distance. Among the poison frogs studied so far, it is remarkable that A. trivittata is the only one known to be able to return from 900 m (which perhaps is a remarkable homing distance for anurans in general), while maximum return distances in other species are less than 50% of this. Ameerega trivittata is one of the largest poison frogs (maximum snout-vent length 55 mm). However, long distance homing was not explained by the species' body size. We rather expect that 'good knowledge' of the general area (in terms of integration of learned landmarks) that frogs live in is the reason for the ability of long distance homing in our focal taxon. [ABSTRACT FROM AUTHOR]

Anuran amphibians are a key group when assessing diversity patterns in Amazonia. Of the many different habitat types in this region exploited by anurans, floating meadows have received little attention. These are semi-anchored, thick plant mats on the surface of water bodies. We characterize the diversity of anuran communities encountered in this habitat and explore the Amazon River species turnover. Thirty-five species were recorded at seven floating meadow sites. Species richness varied among them but similarity was commonly high between neighbouring floating meadows. Upper Amazon basin sites were more similar to each other than to central Amazonian sites. Central Amazonian sites had limited similarity to each other. High densities in certain anuran species suggest that floating meadows provide highly beneficial habitats, while the presence of other, less common species may result from 'accidental' drift. Yet anuran beta-diversity is relatively similar. We suggest that this is likely due to the fluid nature of floating meadows, which have the ability to disperse anurans. [ABSTRACT FROM AUTHOR]

The article discusses a study which examines Batrachochytrium dendrobatidis (Bd) infection in the terrestrial Alpine salamander. Researchers tested Bd infection in 310 Alpine salamanders inhabiting at different altitudes and found that none of the species were infected with Bd. Possible explanations on the absence of Bd infection are provided, including failure of the researchers to detect Bd, minimized risk of Bd infection due to strictly terrestrial life cycle and resistance of S. atra to Bd because of innate immunity.

The article presents a study that investigates the decline of turquoise dwarf gecko in the two tiny forests of eastern Tanzania. Researchers surveyed the habitats of the geckos at Kimboza Forest Reserve according to its habitat availability. They also studied the threats to the species and the impact of international trade on its population. They found that habitat degradation, method of collection and catching techniques, and international pet trade are the major causes of its decline and threat of extinction.

The article focuses on the development of the geographic information systems (GIS) Species Distribution Models (SDMs) for Jackson's Chameleon in Hawaiian Islands based on the climatic envelop of the species. It says that the data from the native African and the invaded ranges of Trioceros jacksonii in Hawaiian Islands as available through the Global Biodiversity Information Facility was used for the construction of SDM. The SMD suggests that the Jackson's chameleon can find suitable areas on the islands under bioclimatic conditions. Moreover, the interaction of the invasive Hawaiian Jackson's chameleons with native biota was also discovered.

The article presents a study on the neotropical poison frogs Ranitomeya (R.) imitator and R. fantastica, to determine whether there more than one mode of breeding resource between the two species. It states that R. imitator and R. variabilis coexist through functional resource partitioning and niche segregation and avoid competition against each other through specialization. The study, which was conducted at a forest in San Martin, Peru from July 22 to November 17, 2008, involves the use of 125 artificial phytotelmata with 500 milliliters (ml) of water that were attached to 25 trees in the study site. The result shows that niche partitioning, such as the size of breeding pools, could be a sufficient niche differentiation to avoid competition between the R. imitator and R. fantastica.

The article discusses a morphological study on the systematics of Phrynobatrachus scheffleri and P. kakamikro sp. n. which are frog species both found in East Africa. It says that the study used the specimens from museum collections and that morphological characters include snoutvent length (SVL), dorsal skin texture, and interorbital space (IO). It tells that DNA Sequence alignment was conducted and that frequency information was acquired via Fast Fourier Transformation. It explores the physical characteristics, the molecular genetics, and the distribution and life history of P. scheffleri and P. kakamikro sp. n.

The article presents a study on male harlequin toads (Amphibia: Atelopus hoogmoedi) site fedility, home range and habitat utilization during rainy season at Brownsberg Nature Park, Suriname. It says that field work was conducted in the area, 19 male toads were observed and the dorsal and ventral pattern of specimen was photographed with a Fuji digital camera, and home ranges were examined as fixed kernels. Results show that the relative abundance of male toads was 0.475 per meter, wherein male Atelopus hoogmoedi showed strong site fidelity and the decline of the numbers of captures during the observation indicates little migration or mortality.